氧化亚铁硫杆菌对原生碲矿的浸出工艺及机理初探

发布时间：2018-05-17 13:36

本文选题：氧化亚铁硫杆菌 + 碲矿　；参考：《成都理工大学》2017年硕士论文

【摘要】：碲资源作为国家战略储备资源,对其开发利用已经受到各个国家的重视。经探明,独立碲矿区的碲矿大多为贫矿,富矿较少,传统工艺不能较好地将其开发,为实现独立碲矿的合理性开发,积极开展对微生物浸碲技术的研究具有重大的意义。本论文针对石棉矿区的原生碲矿,通过研究浸矿细菌的活化与驯化,矿石的预处理及各浸矿条件的优化对微生物浸出碲矿效果影响,确立了细菌浸出碲矿的最佳工艺。通过利用原子荧光光谱仪(HFS)和X-射线衍射仪(XRD)分别对Fe3+氧化碲矿、细菌氧化碲矿和细菌氧化单质碲三组实验浸出液中碲的浸出量和氧化后的碲矿物相组成进行分析,考察了细菌和Fe3+在氧化矿物过程起到的作用。再结合扫描电镜(SEM)和傅里叶红外光谱仪(FTIR)分别对细菌氧化碲矿前后矿样表面形貌和细菌在矿样表面吸附情况进行分析,确定了细菌浸出碲矿时存在的作用机理。根据聚乙二醇具有促进细菌氧化Fe2+及硫化矿溶解的特点,确定了聚乙二醇添加的最佳质量浓度和相对分子质量,考察了聚乙二醇在最佳相对分子量和质量浓度时对细菌浸出碲矿效果的影响。本实验主要内容和结果如下:(1)氧化亚铁硫杆菌浸出碲矿工艺的考察。通过对细菌在9K培养基中的活化培养和在含有亚碲酸及碲矿矿浆的培养基中驯化培养,使细菌对Fe2+的氧化活性不断提高,对亚碲酸盐耐受性不断加强以及在矿浆中的适应期也变短。活化驯化的细菌可以用来浸出碲矿。矿样经酸化后,培养基pH值可稳定在2.0左右,并在温度为30 oC,pH值为2.0,细菌接种量为10%,矿浆浓度为40 g/L,摇床转速为150 r/min的浸矿条件下时,细菌对碲矿浸出效果最好,浸出24天后,碲的浸出量可达154.78 mg/L,浸出率为47.77%。(2)氧化亚铁硫杆菌浸出碲矿初步机理的考察。通过HFS和XRD对Fe3+氧化碲矿、氧化亚铁硫杆菌氧化单质碲及碲矿三组实验浸出液中碲的浸出量和氧化后的碲矿物相组成分析,得出细菌浸出碲矿时Fe3+能将矿样中的低价碲氧化为单质碲,但不能氧化为亚碲酸与碲酸;在细菌的作用下,单质碲被氧化为碲酸,实现了碲矿中碲的浸出。通过结合SEM和FTIR分别对细菌氧化前后的碲矿表面形貌以及细菌在碲矿表面吸附情况进行分析,得出细菌代谢产物Fe3+对碲矿表面有一定侵蚀作用和细菌浸出碲矿时在碲矿表面有一定的吸附。(3)聚乙二醇强化氧化亚铁硫杆菌浸出碲矿的考察。通过考察聚乙二醇的相对分子质量和质量浓度对细菌氧化Fe2+及碲矿溶解的影响,得出当聚乙二醇相对分子质量为2000,添加质量浓度为0.09%时,促进细菌对Fe2+的氧化活性和碲矿溶解性最好。在添加最佳相对分子质量和质量浓度的聚乙二醇作用下,细菌浸出碲矿的效果有了较大的提升。相比只添加细菌组,浸出24天后,碲的浸出率为83.91%,细菌对碲的浸出率增高了1.45倍,细菌提前3 d开始对碲矿进行氧化。研究结果表明,氧化亚铁硫杆菌经活化与驯化后,细菌的浸矿活性得到了提高,可以用来浸出碲矿。经各浸出条件优化,细菌对碲矿浸出效果得到了提升。细菌浸出碲矿过程中,存在细菌对碲矿的间接浸出机理。对细菌氧化碲矿机理的了解,可为进一步提高细菌对碲矿的浸出效果提供理论指导。聚乙二醇通过提高细菌的氧化活性和矿样的溶解量,增强了细菌对碲矿的氧化效果。这些研究可为以后更好地开发利用原生碲矿资源提供理论依据和技术指导。
[Abstract]:Tellurium resource is a national strategic reserve resource, and its exploitation and utilization has been paid attention to by various countries. It is proved that tellurium ores in the independent tellurium mining area are mostly poor and rich, and the traditional technology can not be developed well. It is very important to study the tellurium tellurium technology for the development of independent tellurium and to develop the tellurium technology. Aiming at the primary tellurium ore in asbestos mining area, the best process of leaching tellurite by microorganism leaching is established by the study of the activation and acclimatization of bacteria in the ore leaching, the pretreatment of ore and the optimization of the conditions of ore leaching, and the optimum process of leaching tellurite from bacteria is established by using atomic fluorescence spectrometer (HFS) and X- ray diffractometer (XRD) to oxidize Fe3+, respectively. Tellurite, tellurite and tellurium are three groups of tellurium, and the composition of tellurium in the leaching solution and the composition of the phase composition of the tellurium after oxidation are analyzed. The effect of bacteria and Fe3+ on the oxidation process is investigated. The surface of tellurite oxide sample surface before and after the tellurite is combined with scanning electron microscopy (SEM) and Fourier infrared spectrometer (FTIR). The adsorption of morphologies and bacteria on the surface of ore samples was analyzed, and the mechanism of action of tellurite leaching was determined. According to the characteristics of polyethylene glycol to promote the oxidation of Fe2+ and the dissolution of sulfide ore, the optimum mass concentration and relative molecular mass of the polyethylene glycol were determined, and the optimum relative molecular weight and the molecular weight of polyethylene glycol were investigated. The main contents and results of this experiment are as follows: (1) study on the technology of tellurite leaching of Thiobacillus ferrooxidans. By acclimating the bacteria in the medium of 9K and domestication in the medium containing tellurite and tellurite pulp, the oxidation activity of bacteria to Fe2+ is constantly improved. The tellurite tolerance is constantly strengthened and the adaptation period in the pulp becomes shorter. The activated acclimated bacteria can be used to extract tellurite. After acidification, the pH value of the medium can be stabilized at about 2, and the temperature is 30 oC, the pH value is 2, the bacterial inoculation amount is 10%, the pulp concentration is 40 g/L, and the rocking speed is 150 r/min under the leaching condition. The leaching of tellurium is the best. 24 days after leaching, the leaching amount of tellurium can reach 154.78 mg/L. The leaching rate is 47.77%. (2) 47.77%. (2) Thiobacillus ferrooxidans leaching tellurite. The leaching amount of tellurium in the Fe3+ oxide tellurite, the oxidation of tellurium and tellurite in three groups of tellurium oxide and tellurium after oxidation of tellurium oxide and the oxidized tellurite ore Phase composition analysis shows that Fe3+ can oxidize tellurium in the ore sample to tellurium, but it can not be oxidized to telluric acid and telluric acid. Under the action of bacteria, tellurium is oxidized to telluric acid, and tellurium leaching is achieved in tellurite. By combining SEM and FTIR, the surface morphology of tellurite before and after oxidation of bacteria and bacteria in bacteria are respectively combined. The adsorption of Tellurium on the surface of tellurite is analyzed. It is concluded that the bacterial metabolite Fe3+ has some erosion on the surface of tellurium and the adsorption of tellurite on the surface of tellurium when the tellurite is leached. (3) the study on the leaching of tellurite by the strengthening of Thiobacillus ferrooxidans by PEG. By investigating the relative molecular mass and mass concentration of PEG to oxidize F The effect of e2+ and tellurite dissolution is that when the relative molecular mass of polyethylene glycol is 2000 and the mass concentration is 0.09%, the oxidation activity of Fe2+ and the solubility of tellurium are best. The effect of the bacteria leaching of tellurite by the addition of the best molecular weight and the mass concentration of polyethylene glycol has been greatly improved. 24 days after leaching, the leaching rate of tellurium was 83.91%, the leaching rate of tellurium increased by 1.45 times, and the bacteria began to oxidize Tellurium by 3 D earlier. The results showed that the leaching activity of Thiobacillus ferrooxidans was improved after activation and acclimatization, which could be used to extract tellurite. In the process of leaching tellurium, there is an indirect leaching mechanism of tellurite. The understanding of the mechanism of tellurite can provide theoretical guidance for further improving the leaching effect of tellurite. By improving the oxidizing activity of bacteria and the dissolving amount of the sample, the peg enhanced the tellurium. These studies can provide theoretical basis and technical guidance for better development and utilization of primary tellurium resources in the future.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN304.1

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